If Bumrah finishes at 299 Test wickets while maintaining his present quality, I will rank him as follows:
1. Marshall
2. McGrath
3. Hadlee
4. Steyn
5. Ambrose
6.
7.
8.
9.
10.
11. Chatfield
12. Bumrah
(Chatfield, who was born on the same day of the year as Hadlee (July 3 but 1950 instead of 1951) played half the number of Tests (43) as Hadlee (86) and was integral to Hadlee's success so deserves half of Hadlee's wickets so effectively, Chatfield has > 300 Test wickets)
If Bumrah gets to 300 Test wickets, this will be the ranking (he now moves ahead of Chatfield because of slightly better quality):
1. Marshall
2. McGrath
3. Hadlee
4. Steyn
5. Ambrose
6. Bumrah
For 301 Test wickets, it'll be:
1. Marshall
2. McGrath
3. Hadlee
4. Steyn
5. Bumrah
6. Ambrose
For 302 Test wickets:
1. Marshall
2. McGrath
3. Hadlee
4. Bumrah
5. Steyn
6. Ambrose
For 1000 Test wickets at an average of 5 runs/wicket:
1. Marshall
2. McGrath
3. Hadlee
4. Bumrah
I made a running analogy once before, and another one applies here:
Hadlee = Roger Bannister
Bumrah =
"Gunder the Wonder" Hägg